vga_switcheroo: Set active attribute to false for audio clients

The active attribute in struct vga_switcheroo_client denotes whether
the outputs are currently switched to this client. The attribute is
only meaningful for vga clients. It is never used for audio clients.

The function vga_switcheroo_register_audio_client() misuses this
attribute to store whether the audio device is fully initialized.
Most likely there was a misunderstanding about the meaning of
"active" when this was added.

Comment from Takashi's review:

"Not really.  The full initialization of audio was meant that the audio
is active indeed.  Admittedly, though, the active flag for each audio
client doesn't play any role because the audio always follows the gfx
state changes, and the value passed there doesn't reflect the actual
state due to the later change.  So, I agree with the removal of the
flag itself -- or let the audio active flag following the
corresponding gfx flag.  The latter will make the proc output more
consistent while the former is certainly more reduction of code."

Set the active attribute to false for audio clients. Remove the
active parameter from vga_switcheroo_register_audio_client() and
its sole caller, hda_intel.c:register_vga_switcheroo().

vga_switcheroo_register_audio_client() was introduced by 3e9e63db
("vga_switcheroo: Add the support for audio clients"). Its use in
hda_intel.c was introduced by a82d51ed ("ALSA: hda - Support
VGA-switcheroo").

v1.1: The changes above imply that in find_active_client() the call
to client_is_vga() is now superfluous. Drop it.

Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
[danvet: Add Takashi's clarification to the commit message.]
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>